Privacy Requirement Modeling and Verification in
Cloud Computing
Jin, Wang
College of Computer Science and Technology
Nanjing University of Aeronautics and Astronautics
Nanjing, China
woodenwang55@hotmail.com
Abstract—Cloud computing, the architecture which shares
dynamic heterogeneous characteristics in the cross-layer service
composition, has affected traditional security, trust and privacy
mechanisms which are mainly based on data encryption and
access control. Approaches that can support accurate privacy
requirement description and verifiable compliance between the
privacy requirement and system practice need to be developed to
fit this new paradigm. To tackle the issues of privacy
requirement modeling and verification in cloud computing, a
framework that supports model checking consistency, entailment
and compliance with the formal definition of privacy
requirements and privacy model of cloud application is proposed.
This paper provides an overview of the scientific research
problem, approaches to solve the problem and ways to evaluate
the solution found by the research related PhD thesis.
Keywords—Cloud computing, privacy requirement, model
checking, formal model
I.
PROBLEM
Scalability, on-demand access and network-based message
delivery are three core characteristics of cloud computing [1].
As a scalable and hierarchical distributed collaboration
paradigm, cloud computing is envisioned as an XaaS (X As a
Service) architecture, combined with the advantage of reducing
cost by sharing computing and storage resources [2]. Although
there is a large push towards cloud computing, security and
privacy are the major challenges which inhibit the cloud
computing’s wide acceptance in practice. A survey conducted
by the US Government Accountability Office (GAO) states
that “22 of 24 major federal agencies reported that they were
either concerned or very concerned about the potential
information security and privacy risks associated with cloud
computing” [3]. Different from the traditional architecture in
which users have full control of their privacy data, the internal
operations of cloud computing software systems are usually
transparent to the users and once the privacy data of the users
are collected, they will lose control over it.
The essence of privacy protection in cloud computing is the
rights and obligations of individuals and service providers with
respect to the collection, use, disclosure, and retention of PII
(Personally Identifiable Information) [4,5]. Providing verifiable
mechanism in design phase to ensure that the practice of
software is compliant with the privacy requirement is one of
the most important principles in privacy related standards and
regulations such as OECD [6] and ISO29100 [7]. The issues
appearing in this principle are manifold.
Firstly, we need an approach to precisely describe the
privacy requirement. On the one hand, due to the ambiguous
and inconsistent essence, natural language is essentially
unusable to depict a user concerned privacy
requirement. On
the other hand, directly using a specification language, such as
Linear Temporal Logic (LTL) and Description Logics (DL), is
too
complicated
to be implemented by the requirements
analysts and system designers. Therefore, we must establish
one privacy requirement description method that can make a
balance between the expressiveness and the applicability.
Secondly, considering the multi-participant and outsource
nature of cloud computing, we must guarantee there is no
conflict among different participants which means the privacy
requirement among different participants should be
consistent with each other.
Thirdly, some laws and regulations in different
application contexts, such as the Children Online Privacy
Protection Act (COPPA), the Health Information Portability
and Accountability Act (HIPAA) and the Gramm–Leach–
Bliley Act (GLBA), are proposed to enforce the privacy
requirements of each participant and we must make sure the
privacy requirements entail certain privacy regulations and
laws.
Finally, we need to verify the compliance between the
cloud computing system practice and requirements. To
support the verification, a formal model of privacy
requirements and the specified cloud computing privacy model
are needed. Moreover, to overcome the space explosion
dilemma in traditional model checking, there should be some
reduction method to make our verification represent real-life
systems and not just toy examples.
II. RELATED
WORK
A. Privacy Requirement Description
Current privacy policy definition methods can be classified
into four categories, access control model based on
RBAC(Role-Based Access Control), access control models
using Markup Language, Semantic-web policy frameworks
using description logic and declarative language with formal
semantics.